Colorants, both synthetic and derived from natural sources, are used in many foods, drugs, and cosmetics.
The use of colorants for foods and pharmaceuticals has been a topic of controversy in recent times because of safety concerns. Although the use of synthetic organic colorants in food products was first regulated in the United States in 1886, further attention was directed to the results of toxicological studies conducted on color additives by the U.S. Food and Drug Administration in the 1950's and 1960's. As a results of such toxicological examinations, the list of colorants which are still approved for use in foods, etc. is very limited.
For example, FD&C Red No. 2 (amaranth), a synthetic colorant, was banned in the United States in 1976 because uncertainty lingered concerning its role as a carcinogenic agent. FD&C Red No. 4 has also been banned from internal use, although it is permitted for external use in drugs and cosmetics. Other U.S. certified food colorants are suspected carcinogens. One such colorant is FD&C Red No. 40, because p-cresidine, an intermediate used in its manufacture, is a known carcinogen.
In view the strict regulation of synthetic colorants and the accompanying adverse publicity concerning the same, colorants derived from natural sources have been gaining popularity. However, even colorants derived from natural sources have been carefully scrutinized. Thus, for example, the use of beet color is restricted to dehydrated beet powder and juice concentrate.
One edible colorant which is derived from natural sources is carminic acid (C.I. Natural Red No. 4; 75470). Carminic acid is extracted from the cochineal or "coccus cacti," an insect which lives on the leaves of the cactus. Carminic acid is soluble in water and occurs as "cochineal extract" or as a powder containing up to 99% carminic acid. From the cochineal extract an aluminum or calcium aluminum lake on aluminum hydroxide substrate is prepared called CARMINE (CAS.REG. No. 190-654). Carmine occurs as bright red pieces or as a red powder which is practically insoluble in cold water and dilute acid. It is soluble in alkaline solution and from insoluble pigment becomes a dye. Carminic acid and carmine have been used in the food, cosmetic and pharmaceutical industry. Carminic acid is also used as a textile dye.
Although carminic acid and solubilized carmine are extensively used to provide red color to foods and cosmetics, they present the disadvantage of not being usable in acidic media. More particularly, carminic acid is bluish-red in alkaline media and orange-yellow in acidic media. In addition, solubilized carmine precipitates in acid media e.g., at pH 5 or lower.
This result is illustrated in U.S. Pat. No. 1,616,739 (Bost) which describes a carmine-containing colorant for orange drinks and other acidic beverages and a method of preparing the same. Glycerin and carmine are mixed and heated until a homogenous mixture is obtained, and this mixture is treated while hot with aqueous sodium hydroxide. Ammonium hydroxide is added and the mixture is boiled to remove part of the water present and to completely dissolve the carmine in the alkaline glycerin. Phosphoric acid is added with continued boiling.
The resulting solution is red. However, when added to an acidic flavorant, it undergoes a color change from red to orange, thereby providing the orange flavored beverage with the desired orange color.
It is therefore an object of the present invention to provide a red colorant which is suitable for use in foods, drugs and cosmetics which is substantially color stable in medias of varying pH, in satisfaction of the long-term need for a red food coloring agent useful in acidic media, e.g. beverages.
It is another object of the present invention to provide an edible red colorant based on carminic acid which is color stable in acidic media and which may be used in foods, drugs or cosmetics.
It is another object of the present invention to provide a red colorant composition based on carminic acid which does not contain aluminum.